actual filter gph flow rates...

[speedemon]

hi all
i see here and on a lot of forums all over ppl always saying you need 'x' amount of gallons per hour for different setups and then use what the manufacture says on the box as a guide...
what i am saying is for example it isn't uncommon to hear that for a cichlid or goldfish tank you need 10x gph, a 70 gal tank would need 700gph, so if you were to buy two rena xp3's rated at 350 gph you would be fine with a total of 700gph, HOWEVER the actual flow rate of a rena xp3 after filter media and pipes is only 180 gph, so even having two would only give you 360 gph, which is only about 5x the filtration...


so the question is when ppl are saying you need 10x or between 2-3x filtration are they going by actual gph or advertised gph??

and as a side note has anyone made a collection of data of all the major filters out there and their actual gph?

i tested my xp3's using a 2qt jug, and used a stop watch to time how long it took to fill it, 9.98 sec, divided that by 60, 6.01, multiplied that by 2, 12.02, multiplied that by 60, 721.44 and finally divided that by 4 which gave me 180.36 gph.
i thought it would be cool if everyone did this with there filters and we made a data list of all the filters we all use for reference...

 

[speedemon]

bumb...
i'd like to also that i am not trying to bash the companies who make these fine filters, and a lot of them in small print actually state the real gph right on the box, rena lists the xp3 at 185gph i believe which is pretty dead on with mine, i do have mine packed with a lot of bio media though...

but i am still curious as to what ppl mean when they say you should be filtering a certain tank at 10x an hour, goldfish for e.g., in that case my 46 gal tank would need 3 xp3's which i think is crazy!

 

[roka64]

bumb...
i'd like to also that i am not trying to bash the companies who make these fine filters, and a lot of them in small print actually state the real gph right on the box, rena lists the xp3 at 185gph i believe which is pretty dead on with mine, i do have mine packed with a lot of bio media though...

but i am still curious as to what ppl mean when they say you should be filtering a certain tank at 10x an hour, goldfish for e.g., in that case my 46 gal tank would need 3 xp3's which i think is crazy!

Are you talking filtering GPH or flow...?

 

[speedemon]

filtering gph...

 

[SpeedEuphoria]

Put it this way, if you have a heavily planted FW tank then you can use ~10x real flow.

For an unplanted tank its a good Idea to have 10x the claimed flow or 5x real world flow.

You dont need to get these numbers from "filtering" necessarily, in an unplanted tank it would be a good idea though. You can just add or use power heads in areas to make sure the water keeps moving and doesnt become stagnate. This will also help your "filter" because crap that would normally get blown to the side then the flow slows so it sinks and piles up in the area with least flow, so putting a PH there will make it so more crap gets back to the filter inlet.

In a planted tank, the water movement is more important as the plants block and diffuse the water flow, but the plants also use up some toxic nutrients(ammonia,ect..). Its also important for a higher tech(high light/CO2) tank b/c the more water movement will make sure all of the plants have a good supply of nutrients and CO2.

like currently I have a claimed flow of 260GPH and 400GPH in my 55G tank, so 660GPH claimed, prob like 400GPH(180/220) real flow and its not too much. When my plants grow in more I could prob use another 200GPH "claimed".